ES2559815T3 - Cartridge piston - Google Patents

Abstract

Piston (1, 50, 51) for a cartridge to preserve a filling mass in a reserve chamber of the cartridge, comprising a piston body (2, 52), having a transport side (3, 53) as well as a drive side (4, 54) opposite the transport side (3, 53) and a piston liner (5, 55), wherein the piston liner (5, 55) is arranged around a piston axis ( 9) and the piston body (2, 52) is perimetrically surrounded by the piston liner (5, 55), wherein the piston liner has a sealing element to establish a fluid-tight connection between the sealing element of the piston liner (5, 55) and an inner wall of the reservoir chamber of the cartridge, in such a way that the sealing element, in the assembled state, establishes a fluid-tight connection between the transport side ( 3, 53) and the drive side (4, 54), and the piston body (2, 52) contains a first and a second ventilation element (60, 61), whereby the transport side (3, 53) and the drive side (4, 54) can be connected to each other via a bore (75) in each case, characterized in that the piston body (2, 52) has a ventilation slit (71, 73), which is made and arranged on the transport side (3, 53) in such a way that, when the piston (1, 50, 51) is inserted into the cartridge containing the filling mass , gas can be conducted through the ventilation slit (71, 73) to an inlet opening (62, 63) which opens into the bore (75).

Description

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DESCRIPTION

Cartridge piston

The invention relates to a piston for a cartridge, especially for extracting solid dough-filled masses, which contains a ventilation device. Filler doughs may contain mixtures of various components. These filling masses are introduced into a reserve chamber of the cartridge. Following this the filled cartridge of the filling mass is closed by the piston. Through the ventilation device, all the air between the piston and the filling mass must escape.

A piston of this type is known for example from DE 200 10 417 U1. The piston has a first piston part, which is provided with a sealing skirt. The sealing skirt makes contact with a cartridge wall. The piston also has a valve element, which is configured as a second piston part. This valve element has a cylindrical-circular wall part, which is placed in a depression of the first piston part and on the basis of this depression is interlocked with the first piston part by means of a retained joint. The cylindrical-circular wall part is transformed into an arc like a valve stem. The valve stem passes through a cylindrical bore on the first piston part and has a valve cone, which is determined to settle on a valve lip of the first piston part. The retaining joint is interrupted by a small air channel, with which a filtering section is formed between the wall of the first piston part and the inner side of the cylindrical-circular wall part of the valve element. Other variants for such an air channel are known from EP 0351 517 A1, EP1738834 A1 or US2005 / 0029306 A1.

Because a piston according to DE 200 10 417 U1, EP 0351 517 A1, EP1738834 A1 or US2005 / 0029306 a1 is relatively complicated to manufacture, different simplifications of this construction mode have been proposed. For example, there are pistons that, instead of a ventilation valve, contain a hole through which air can escape.

However, these known pistons have proved unsuitable for extracting filler doughs for the following reasons. On the one hand there is an objective conflict between the size of the drill and the speed of settlement of this piston. For example, in EP 1 338 342 A1 two small holes are shown, through which a connection between the transport side and the drive side can be achieved. The diameter of the holes has to be sized so small, that a passage of filling mass from the transport side to the drive side can be prevented, so that the holes have to configure a filtering section as in DE 200 10 417 U1. Correspondingly, the holes are designated as capillary channels. That is to say, that capillary forces prevent the filling mass coming through the holes to the drive side. Therefore, the seat speed for this piston is small, since during the piston seat it is necessary to ensure that the air between the filling mass and the piston can be evacuated through the holes.

The larger the hole, the faster the air can escape from the intermediate chamber between the piston and the filling mass, when the piston is inserted into the reserve chamber. Obviously, a larger hole has the consequence that a larger volume of filling mass can pass through that hole and increases the risk of contamination of the hole on the actuation side of the piston.

The term piston settlement means the installation of the piston in the reserve chamber of the cartridge. The reserve chamber filled with the filling mass of the cartridge is sealed tightly to the fluids by means of the piston. For this, the piston is placed on the inlet opening of the cartridge and a little is introduced into this reserve chamber, almost always until the actuation side of the piston is flush with the inlet opening, that is, no part of the piston protrudes above the entrance opening.

Another problem occurs when the piston is seated, especially for semi-liquid or pasty filling masses. A semi-liquid or pasty filling mass of this type does not have a defined level of filling in the reserve chamber, as is known for a liquid, that configures a meniscus. The surface of a semi-liquid or pasty filling mass is not flat, but rather has elevations and depressions. Therefore, the filling level can be much higher locally than can be expected according to the average value. The piston settling process, however, is normally carried out with a controlled path, that is, the piston is introduced into the reserve chamber of the cartridge along a preset travel section. That is, the piston can come into contact with the elevations of the filling mass, before the piston has reached its final position. If an elevation affects the ventilation opening, it is obstructed and an air bubble can remain between the filling mass and the transport side of the piston. If the settlement process continues, this air bubble is compressed.

Although the filling mass does not come out directly during the settling process through the drill to the drive side, it could be caused by a slow decrease in the internal pressure increased during the settling process an entry of the filling mass into the drill. This drill is true that in a subsequent work step it closes, for example it is welded. However, if filling mass is found in the hole, the welding process may be impaired, for example, the welding is incomplete, so that

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Filling mass can flow through the hole to the piston drive side. That is, a leak occurs, which can lead to the preservation of the filling dough no longer being guaranteed.

EP 1 338 342 A1 of the exposed genus describes a piston, in which, when inserted into a cartridge containing a filling mass, gas can be conducted, through two capillary passages, from a transport side to a drive side. To get to one of the capillary passages, the gas must meet it on the transport side very close to the capillary openings.

The task of the invention is to create an improvement for said piston, so that the filling masses can be confined tightly to the fluid filling masses in a reserve chamber of a cartridge, such that the filling mass in the cartridge it can be stored for at least a limited period of time. The piston must be able to be introduced by means of commercial extraction devices in the reserve chamber of the cartridge.

This task is solved by means of a piston for a cartridge, where the cartridge contains at least one reserve chamber to conserve a filling mass. The piston comprises a piston body, which has a transport side as well as a drive side opposite the transport side and a piston sleeve. The piston sleeve is arranged around a piston shaft and the piston body is surrounded perimetrically by the python sleeve. The piston sleeve has a sealing element for establishing a fluid tight connection between the sealing element of the piston sleeve and an inner wall of the cartridge reserve chamber, such that the sealing element, in the mounting state, establishes a fluid tight connection between the transport side and the drive side. The piston body contains a first and a second ventilation element, whereby the transport side and the actuation side of the piston can be connected to each other through a bore in each case, and the piston body has a slit of ventilation, which is carried out and arranged on the transport side, such that, by inserting the piston into the cartridge containing the filling mass, gas can be conducted through the ventilation slit to an inlet opening that flows into the drill. At least one of the holes may have a cross section in particular circular. The holes run through the piston body, and thus are located inside the piston body, that is, the holes are not arranged on an inner or outer edge of the piston body.

The provision of a first and a second hole has the advantage that ventilation is still guaranteed, even if a hole is obstructed by an irregular surface of the filling mass during the settling process. In addition, the piston settling speed can be increased, since the air flow increases if both holes are free of filling mass.

Preferably, at least one of the first and second ventilation elements is provided a first inlet opening and a second inlet opening, which flow into the hole. For this, a first and second connection channel can be provided in each case. The joint channel and / or the drill run from the drive side to the transport side of the piston. In particular, the first and second joining channels can lead to a common collecting channel, where the collecting channel can be the drill. Alternatively to this, each entry opening can have its own hole, which joins the transport side to the drive side.

The piston body has a ventilation slit, which is arranged on the transport side. Through the ventilation slit, the formation of gas bubbles, which are hugged by the piston surface on the transport side and the filling mass, can be avoided. The ventilation slit offers in any case the possibility of gas being conducted to the inlet opening of the ventilation elements. Especially the ventilation slit is attached to the first and second inlet opening.

At least one of the holes has a longitudinal axis, which is oriented essentially parallel to the longitudinal axis of the piston. This variant can be produced especially easily.

At least one of the inlet openings may be oriented at an angle to the longitudinal axis of the ventilation element. In particular, the longitudinal axis of the inlet opening is arranged at an angle to the longitudinal axis of the bore of the ventilation element. If a filling mass wants to reach an entrance opening of this type, this entry opening is not immediately clogged.

The angle is in this case greater than 10 ° to 90 ° inclusive, preferably greater than 20 ° to 90 ° inclusive, especially preferably greater than or equal to 30 ° to 90 ° inclusive.

The drill can also contain at least one inflection, a curvature or a throttle element. This lengthens the path for a filling dough that enters the hole. The curvatures, inflections or throttle points form obstacles to the flow, by means of which it is prevented that mass of filling can reach the actuation side of the piston.

Preferably, the minimum bore diameter is larger than 1/40 of the piston diameter.

A piston according to one of the embodiments can be configured as an annular piston. A piston of this type comprises an inner piston sleeve, wherein the inner piston sleeve limits the piston body by a

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inner side turned towards the piston shaft, comprising an inner sealing element for establishing a sealing contact with a wall of an inner tube disposed within the inner piston sleeve.

The piston can be shaped in such a way that a protective element is applied to the piston body on the transport side. A protective element of this type may be made of a material that has a greater resistance with respect to the filling than the piston material. In this way the protective element can develop a protective function for the piston material.

The protective element may contain a ventilation element. This ventilation element is used to extract gases from gaseous occlusions from the inner chamber of the piston, which are produced, for example, during the settlement of the piston described above. In the case of gas, it can be especially air.

Reinforcing ribs may be arranged on the actuation side of the piston. The provision of reinforcement ribs ensures that the piston remains stable in shape, even if the piston undergoes a pressure load by means of an extractor.

An anti-tip element may be arranged on the actuating side of the piston, which is used to improve the guidance of the piston in a cartridge. The piston is guided with anti-tip protection by means of the anti-tip element, which is in contact with the wall of the cartridge, that is, the axis of the piston body coincides with the axis of the piston. The anti-tip element ensures that the transport side is arranged in a plane perpendicular to the piston axis or, if the transport side is not flat, that the points of the piston surface on the transport side, which are characterized by a certain radius and a certain height, they are located along the penimeter in essentially the same perpendicular plane. If the piston overturns the requirement for these points is not met. By means of such an anti-tip element, a contact on the side of the penimeter can be maintained with the cartridge wall during the entire extraction process, such that together with the guiding element described above, a deflection of the piston can be avoided.

The advantages of the special features that the annular piston can present correspond to the advantages, such as those mentioned above in relation to a piston for a cylindrical inner chamber or an inner chamber of another geometric shape without internal structures.

An extraction device comprises a piston according to one of the previous embodiments. The extraction device comprises, in particular, a cartridge for extracting several components, wherein the components are arranged in reserve chambers of the cartridge, arranged next to each other or coaxially. Also, the extraction device can comprise an extractor apparatus, by means of which the piston can be attached to the drive side.

The piston is used particularly advantageously, according to one of the previous embodiments, for the extraction of fillers containing solids, such as sealing masses or adhesives.

The invention is explained below based on the drawings. Here they show:

fig. 1 an extraction device containing in each case a piston in a reserve chamber filled with filling dough,

fig. 2a a cut through a piston according to a first embodiment according to the state of the art, fig. 2b a cut through a piston according to a second embodiment according to the state of the art, fig. 2c a cut through a piston according to fig. 2b in a perspective exposure, fig. 3 a representation of a coaxial cartridge,

fig. 4 a view on the transport side of a piston according to a first embodiment of the invention,

fig. 5 a view on the actuation side of the piston according to fig. 4,

fig. 6a a cut through a piston half of the piston according to fig. 4 in a simplified embodiment,

fig. 7 a cut through a piston half of a piston according to a second embodiment of the invention,

fig. 8 a section through a piston half of a piston of a third embodiment of the invention, fig. 9 a section through a piston half of a piston of a fourth embodiment of the invention, fig. 10 a cut through a piston half of a piston of a fifth embodiment of the invention.

Fig. 1 shows an extraction device, comprising a cartridge 17 for extracting various components asf

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as a static mixer 20, which is applied and attached to the outlet element of the cartridge.

The static mixer 20 contains a mixer housing 21, in which there is an arrangement of mixing elements 22. The mixer housing 21 contains at its first end 23 two inlet openings 25, 26 separated from each other, which are formed as nozzles , which can be plugged into corresponding outlet openings 44, 45 of the cartridge or fit into them. The second end 24 of the mixer housing 21 contains an outlet opening 27, through which the mixture can exit to be fed to the desired application. The mixer housing 21 and the arrangement of mixing elements 22 can be made as two separate construction pieces, which if necessary can move relative to each other.

The mixer housing 21 is connected by means of a fastener 40 to the outlet element 46 of the cartridge, where the joint can be made as a screwed or bayonet joint, as explained for example in EP0730913 A1. According to the embodiment according to fig. 1 a first and a second fixing element 41, 42, which are arranged on the clamping element 40, engage in a corresponding first and second housing elements 47, 48 of the exit element 46. The clamping element 40 can rotate in relation to the outlet element 46, where a rotating element 49 can be provided, whereby the clamping element 40 can rotate relative to the outlet element 46 and the first end 23 of the mixer and the fixing elements 41, 42 they can be engaged with the corresponding housing elements 47, 48.

The cartridge 17 is configured as a multi-component cartridge, wherein the components are arranged in cartridge cavities arranged next to each other or coaxial with respect to each other. These cavities will now be called reserve chambers for the filling dough. The reserve chambers can be closed by means of the pistons 50, 51, and the outlet openings 44, 45 of the outlet element 46 can be closed by a closure cap not shown or by a static mixer, which is already clogged by hardened mixing product .

The pistons 50, 51 can move along the wall 16 of the corresponding reserve chamber. The pistons are implanted in the reserve chambers through the inlet openings 10, 11. The process of implanting the pistons in the reserve chambers filled with filling mass is called the piston settling.

Naturally, the invention can be used in the same way for pistons for single-component cartridges as well as coaxial cartridges.

Fig. 2a shows a piston, as is known from the state of the art from document DE 200 10 417 U1. The piston 101 comprises a piston body 102, which is almost always made of plastic material by an injection molding process. The piston 101 is preferably used to extract a filling mass from a cartridge, especially from flowing or pasty media. A wall 116 of the cartridge 117 is shown. The piston 101 slides along the wall 116 and displaces the filling out, during this movement, through an outlet opening not represented by the cartridge. The piston side 101 on the middle side is now referred to as the transport side 103. To put the piston in motion and keep it moving, a pressure force is applied by means of an extractor. The extractor apparatus, of which a pusher element 118 is shown, is located on the side of the piston opposite the transport side 103. This side is now referred to as the drive side 104.

The piston body 102 is thus limited by the drive side 104, the transport side 103 and a piston sleeve 105. The piston sleeve 105 forms the joint between the drive side 104 and the transport side 103 In the majority of cases, the piston body has a large number of recesses or is structured as a hollow body. For reasons of saving material and because of the difficulties, inherent to the injection molding of thick-walled building parts, pistons of this type are manufactured as thin-walled building pieces and from a diameter of a few centimeters. The necessary stability is obtained by the piston by means of reinforcing ribs 115. In addition, the piston may contain a protective element 113. A protective element 113 may be configured as a protective disk, whose function is to shield the piston body from the front. to the filling. A protective disk is used when the filler material tends to attack the piston material. This is especially applicable to soft plastic pistons, such as LDPE. LDPE is attacked, for example, by polyester resins and swells.

The piston may also contain a ventilation element. A ventilation element 114 of this type is shown in fig. 1. Gas can escape through this ventilation element, which is located in the reserve chamber of the cartridge 117 between the filling mass and the piston 101, outwards, that is to the actuation side 104, without leaving the filling dough The ventilation element 114 is closed while the cartridge is stored in the filling state. That is, the pivot 119 of the ventilation element 114 is located on the corresponding seat 120.

If the filling mass is to be removed, the extractor 118 is brought into contact with the piston 101 on its drive side 104. In this respect the extractor also makes contact with the end of the pivot

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119 of the ventilation element 114. The end of the pivot 119 protrudes from the surface, which on the drive side comes into contact with the extractor, such that the pivot rises from its seat 120, when the extractor 118 it comes into contact with the drive side 104. In this respect a flow path for the gas is opened. The gas enters through the flanks 121 of the valve body 122, configured as a protection disk, in the intermediate chamber between the valve body 122 and the piston body 102 and leaves the piston, through the open flow path , through the opening between pivot 119 and seat 120.

The flanks 121 engage through retaining joints with the piston body 102. For this, the flank 121 engages, for example, in a peripheral groove 123 of the piston body 102 on the transport side 103. The flank can also have a skirt of sealing, which engages in a recess of a shoulder 106 of the piston 101. For the gas several small recesses are usually provided on the flank. Following these recesses, a labyrinth joint path can be provided between the piston body 102 and the protection disc 113. In this way, the filling mass that passes through the recesses along this labyrinth joint path can be settled. This way of union has not been represented in more detail in the drawing.

The piston 101 has means against the outflow of filling mass on the drive side 104. For this purpose, at least one sealing skirt is provided along the sliding surface in the wall 116 of the cartridge. The shutter skirt 107 is located on a shoulder 106, which extends between the groove 123 and the wall 116 of the cartridge. The shoulder 106 is configured as an arm, which is attached to the piston body 102. This arm belongs to an annular flange, which extends along the entire penimeter of the piston body 102 and configures a liquid-tight joint with the wall 116 of the cartridge 117.

Fig. 2b shows a cut through a piston half 201 according to a second embodiment, according to the state of the art. A piston half of this piston is also shown in fig. 2 C. The piston 201 comprises a piston body 202, which is almost always made of plastic material by an injection molding process. The piston 201 is used to extract a filling mass from a cartridge, especially of flowing or pasty media. A wall 216 of the cartridge 217 is shown. The piston 201 slides along the wall 216 and displaces the filling mass outward, during this movement, through an outlet opening not shown in the cartridge. To put the piston in motion and keep it moving, a pressure force is applied by means of an extractor, which can be configured analogously to fig. 2nd.

The piston body 202 is thus limited by the drive side 204, the transport side 203 and a piston sleeve 205. The piston sleeve 205 forms the joint between the drive side 204 and the transport side 203 In the majority of cases, the piston body has, as in Figure 2a, a large number of recesses or is structured as a hollow body. The cut of fig. 2b, like that of fig. 2c, is laid by a reinforcing rib 215 of the radially running piston.

The piston contains a ventilation element 214, which is configured as a bore. Gas can escape from this ventilation element 214, which is located in the reserve chamber of the cartridge 217 between the filling mass and the piston 201, outwards, that is to the drive side 204, without the mass being released of filling, if the drill has a sufficiently small diameter. A bore with a small diameter obviously results in a correspondingly high pressure loss, such that the piston seat speed is correspondingly low. The radius of the drill is designated here as R1. The distance between the piston shaft 209 and the end of the sealing skirt 207, which corresponds to the inner radius of the cartridge reserve chamber, is chosen as the piston radius R2. In the present embodiment according to fig. 2c the ratio R1 / R2 is 1/45.

Fig. 3 is a representation of a coaxial cartridge 30. In one coaxial cartridge two or more cylindrical reserve chambers 31, 32 are arranged, coaxially arranged between them, in each case for a component of the filling mass. The internal reserve chamber 31 is completely surrounded by the external reserve chamber 32. The external reserve chamber 32 is annularly arranged around the internal reserve chamber 31. The external limitation of the external reserve chamber is configured as a wall. 16 cylindrical cartridge. The inner reserve chamber 31 is limited by an inner tube 67. The inner and outer reserve chambers each contain a piston 50, 51. The inner piston 50 is located in the inner reserve chamber 31, the annular piston 51 in the outdoor reserve camera 32.

An extractor apparatus 80 is also shown, whereby the inner piston 50 and the annular piston 51 can be moved simultaneously. The extractor apparatus contains an annular pusher 81 to move the annular piston 51 as well as an inner pusher 82 to move the inner piston 50 The inner pusher 82 presents in this embodiment an outer thread 83, which engages in an inner thread 84, which is part of an overlapping element 85. This overlapping element 85 is placed over the inlet openings 33, 34 of the cartridge and it remains attached to it in a stationary manner, while the filling mass located in the reserve chambers 31, 32 is extracted.

The superimposed element is stationary attached to the cartridge. By means of a rotating movement of the inner pusher 82, this is moved relative to the inner thread 84, such that the inner piston 50 moves in the reserve chamber 31 in the direction of the outlet element 86 of the cartridge. The outer pusher

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81 has an upper end 87, which is rotatably mounted on a bearing surface 88 that connects to the external thread 83. A stop 89 prevents a movement of the outer pusher 81 relative to the inner pusher 82. The outer pusher 81 has an end lower 90, which is located on the annular piston 51. The lower end 90 advantageously has an annular bearing surface. A guiding element extends between the upper end 87 and the lower end 90, which is guided through a bore 91 of the superimposed element 85. The annular piston 51 and the inner piston 50 can thus move simultaneously.

Fig. 4 shows a view on the transport side 53 of a piston according to a first embodiment of the invention, which is used for example in a coaxial cartridge according to fig. 3 as an annular piston 51. A first and a second ventilation element 60, 61 are shown in particular. Because the piston has two or more ventilation elements, even with the same diameter of the ventilation element as in the state of the technique can double the volumetric current. That is, the piston seat speed can be correspondingly increased. In this respect, a passage of the filling mass to the actuation side of the piston does not occur surprisingly. Each of the ventilation elements is arranged in a ventilation slit 71, 73. That is, the filling mass must penetrate the narrow ventilation slit and reach the inlet opening of the ventilation element. The inlet opening 62, 63 of the ventilation element is advantageously arranged at an angle with the surface of the piston on the transport side 53.

The ventilation slit, apart from a function as a throttle element for the filling mass, also has the function of detecting gas occlusions at each point of the corresponding piston half and making it possible to transport the gas to the inlet opening 62, 63 corresponding. Especially if the filling mass is semi-liquid, it does not configure a defined surface. The surface of the filling dough may contain elevations and depressions. If an elevation of this type coincidentally directly affects the inlet opening of the ventilation element, an obstruction of the ventilation element may occur. However, if such an elevation impacts a ventilation slit, the gas can flow through the vent 71, 73, passing through the point of incidence of the tip of the elevation of the filling mass, up to the corresponding entrance opening, as shown in detail in fig. 6b The arrows 68 designate in this respect the flow path of the gas.

Fig. 5 shows a view on the drive side 54 of the piston 51 according to fig. 4. The two ventilation elements 60, 61 are located opposite each other, in a symmetrical arrangement in relation to a plane that runs vertically through the longitudinal axis 9 of the piston. They are not located on the reinforcement ribs 65 which run radially and axially, but in an intermediate chamber between these reinforcement ribs. Each of the ventilation slits 71, 73 shown in fig. 4 does not match the reinforcement nerves.

Fig. 6a shows a section through a piston half of the piston according to fig. 4. The annular piston 51 comprises a piston body 52, which is almost always made of plastic material by an injection molding process. The annular piston 51 is preferably used to extract a filling mass from a coaxial cartridge, especially of flowing or pasty media, for which a possible constructive form is shown in fig. 3. A wall 16 of the cartridge has been shown. The annular piston 51 slides along the wall 16 and displaces the filling, during this movement, through an outlet opening not shown arranged in the outlet element 88 (see Fig. 3). The piston side 51 on the middle side is now referred to as the transport side 53. To put the piston in motion and keep it moving, a pressure force is applied by means of an extractor. The extractor, which has not been shown here, is located on the side of the piston opposite the transport side 53. This side is now referred to as the drive side 54.

The piston body 52 is thus limited by the drive side 54, the transport side 53 and by an outer piston sleeve 5 and an inner piston sleeve 55. The outer piston sleeve 5 can have the same structure as described below with respect to figs. 7 to 10 for a single piston 1. The inner piston sleeve 55 forms the inner joint between the drive side 54 and the transport side 53. The inner piston shell 53 limits the piston body 52 on an inner side 59 turned towards the piston shaft 9.

The inner piston sleeve 55 is transformed on the transport side 53 into a shoulder 56. The shoulder 56 is in the exemplary embodiment a thin-walled body with rotational symmetry, which can be seen as a body arm in the cut exposure. of piston 52. The shoulder 56 has an inner guiding element 57 for guiding the piston along an inner tube 67 of the cartridge. The guiding element 57 is suitable for establishing a watertight contact with a wall 66 of the inner tube 67. The guiding element 57 can be specially configured as a sealing skirt. If necessary, several sealing skirts may also be provided. The shoulder 56 comprises a scraper element 58, which has a smaller distance to the transport side 53 than the guide element 57.

The annular piston contains a first and a second ventilation element 60, 61, wherein the second ventilation element has not been shown in the drawing of fig. 6a. In its simplest embodiment, the ventilation element 60 is configured as a bore, which goes from the transport side 53 of the piston to its drive side 54. According to the embodiment represented in fig. 6a the ventilation element has a longitudinal axis 70, which runs essentially parallel to the longitudinal axis 9 of the piston. The element of

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vent 60 has an inlet opening 62 and an outlet opening 72. Gas, especially air, can enter through the inlet opening, which has accumulated on the transport side 53 between the filling mass and the piston surface , in the hole and is driven through the hole in the direction of the outlet opening 72. This variant is especially suitable for filling doughs that essentially form a flat surface.

If two or more ventilation elements are distributed over the piston body 52, local gas occlusions can be avoided. Even if it is desired to obstruct a ventilation element prematurely, because filling mass has entered through its inlet opening 62, the gas still has at least one other ventilation element.

The piston body has reinforcement ribs 65. The ventilation element can be part of one of these reinforcement ribs, which is shown in fig. 6a. The outlet opening 72 of the ventilation element is accordingly arranged on a reinforcing rib, whereby exactly the position of this outlet opening can be fixed. If you want to close the exit opening after the settlement process is finished, it can be welded easily. The position of the outlet opening is fixed exactly and a contraction of the piston can be prevented due to the effect of heat during the welding process, since the reinforcing rib acts analogously to a fixed holder for the outlet opening.

Additionally the piston according to fig. 6a has an outer and inner anti-roll element 18, 64, such that the piston cannot tip over, so that the piston is stabilized in its position relative to the wall 16 of the cartridge.

Figure 6b shows a section through a piston half of the piston according to fig. 4, in which the hole for the ventilation element 60 differs from the hole according to fig. 6a. The ventilation element also contains the bore, which joins the transport side 53 to the drive side 54, a first and a second inlet opening 62, 63.

The ventilation element 60 shown in fig. 6b is lying next to the reinforcing ribs 65. In fig. 6b shows a radially running reinforcing rib, which is arranged outside the ventilation element 60. The reinforcing rib 65 thus has a greater distance to the piston axis 9 than the longitudinal axis 70 of the ventilation element. The ventilation element is configured as a nozzle 74, which protrudes on the drive side 54 above the reinforcing ribs. The greater constructive length of the ventilation element facilitates accessibility for a welding tool, whereby the outlet opening 72 is closed after the piston settles. The closure is necessary to prevent an exit of the filling mass, if the cartridge is stored in such a way, that the piston does not adopt the highest position. In addition to this, it may be necessary, in the case of isolated filling masses, that during storage do not come into contact with the air, because because of this reactions can occur that could modify the characteristics of the mass of filling.

In addition, it is advantageous for the nozzle to be as long as possible, since in this way the channel configured through the bore is lengthened. If the filling mass actually reaches one of the inlet openings, the time can be extended until the filling mass reaches the outlet opening. It is expected that, in the case of semi-liquid filling masses that do not configure a defined filling level but a surface composed of elevations and depressions, it should be added that this filling mass enters the ventilation slit and advances to the opening input 62, 63. Before the exit opening is actually reached, the settlement process will be terminated. For this reason, the outlet opening 72 can be welded, without having to fear contamination thereof with the filling mass. Precisely if the filling mass is semi-liquid, its flow rate is so low, even in the case of a pressure compensation that is likely to occur following the settlement process, that the welding work step has already finished before filling dough can exit through the outlet opening. In this way it can be avoided by means of the embodiment shown in fig. 6b a contamination of the outlet opening. Consequently the outlet opening can be welded tightly to the liquids, such that the filled cartridge can be stored in any position for longer periods.

Fig. 7 shows a piston 1, which can be used for a mono-component cartridge, as an inner piston 50 for a coaxial cartridge or also as one of the pistons 50, 51 of a two component cartridge with reserve chambers located next to each other , as in fig. 1. The piston 1 comprises a piston body 2, which is almost always made of plastic material by an injection molding process.

A wall 16 of the cartridge 17 is shown. The annular piston 1 slides along the wall 16 and displaces the filling mass outward, during this movement, through an outlet opening 44, 45 (see fig. 1) arranged in the outlet element 46, or an outlet opening disposed in the outlet element 88 (see Fig. 3) not shown. The piston side 1 on the middle side is now referred to as the transport side 3. To put the piston in motion and keep it moving, a pressure force is applied by means of an extractor. The extractor, which has not been shown here, is located on the side of the piston opposite the transport side 3. This side is now referred to as the drive side 4.

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The piston body 2 is thus limited by the drive side 4, the transport side 3 and by a piston sleeve 5. The piston sleeve 5 can have the same structure as the outer piston sleeve of figs. 6 to 6b.

The piston sleeve 5 is transformed on the transport side 3 into a projection 6. The projection 6 is in the exemplary embodiment a thin-walled body with rotation symmetry, which in the sectional exposure can be seen as the arm of the body of piston 2. The shoulder 6 has an inner guide element 7 to guide the piston along the wall 16 of the cartridge. The guiding element 7 is suitable for establishing a tight contact with a wall 16 of the cartridge reserve chamber. The guiding element 7 can be specially configured as a sealing skirt. If necessary, several sealing skirts may also be provided. The shoulder 6 comprises a scraper element 8, which has a smaller distance to the transport side 3 than the guide element 7.

The piston 1 contains a first and a second ventilation element 60, 61, wherein the second ventilation element has not been shown in the drawing of fig. 7. The ventilation element 60 has a longitudinal axis 70, which runs essentially parallel to the longitudinal axis 9 of the piston. Gas, especially air, can enter through an inlet opening 62, which has accumulated on the transport side 3 between the filling mass and the piston surface, in a bore 75 and is conducted through the bore 75 in direction to the exit opening 72.

Through the hole a joint is established between the transport side 3 of the piston and its drive side 4. The diameter of the hole can vary, for example the diameter can be reduced as the distance to the transport side increases. According to fig. 7 the diameter path is conical. At the narrowest point, the hole 75 forms a throttle element 69. If it is desired that the filling mass reaches the throttle element, it represents an obstacle to the filling mass, such that the exit of the filling mass in the drive side 4 of the piston is delayed at least until the end of the bore on the transport side, whose outlet opening 72 has been closed in a subsequent working step, is closed with a plug or welded.

Following the throttle element 69, the bore of the ventilation element can be widened again, such that the filling mass that could pass through the throttle element can settle in the borehole, and filling mass is prevented from reaching the proximities. of the outlet opening 72.

The ventilation element has a nozzle 74. The nozzle 74 is essentially the same length as the reinforcing rib 15, such that the nozzle 74 can serve as a support for an extractor 80.

If two or more ventilation elements are distributed over the piston body 2, local gas occlusions can be avoided. Even if it is desired to obstruct a ventilation element prematurely, because filling mass has entered through its inlet opening 62, the gas still has at least one other ventilation element, such that a gas occlusion between the gas is avoided. filling dough and transport side.

In fig. 8 a piston 1 is shown with a variant of the ventilation element 60, which basically corresponds to the ventilation element shown in figs. 4, 5 and 6b for an annular piston.

The piston 1 comprises a piston body 2, which has a transport side 3, an actuation side 4 opposite the transport side 3 and a piston sleeve 5, where the transport side 3 and the actuation side 4 are perimetrically surrounded by the python jacket 5. The piston 1 is preferably a construction piece of plastic material, which has been advantageously manufactured in an injection molding process. The piston sleeve 5 establishes a union between the transport side 3 and the drive side 4, where the piston sleeve 5 is arranged around a piston shaft 9. The piston sleeve is specially configured with a rotation symmetry. , if the piston is determined to be housed in a cylindrical cartridge. The piston sleeve 5 is transformed on the transport side 3 into a projection 6. The projection 6 is in the exemplary embodiment a thin-walled body with rotation symmetry, which in the sectional exposure can be seen as the arm of the body of piston 2. The projection 6 has a guiding element 7 for guiding the piston in a cartridge 1, which is suitable for establishing a watertight contact with a wall 16 of the cartridge 17. The guiding element can be specially configured as a sealing skirt . If necessary, several sealing skirts may also be provided.

On the drive side 4 of the piston an anti-tip element 18 can be arranged, which is used to improve the guidance of the piston in a cartridge. The piston is guided with anti-tip protection by means of the anti-tip element 18, which is in contact with the wall 16 of the cartridge 17, that is, the axis of the piston body 2 coincides with the axis of piston 9. By the element anti-tip 18 ensures that the transport side 3 is arranged in a plane perpendicular to the piston axis 9 or, if the transport side 3 is not a flat surface or contains segments that are not located in a plane, that the points of the piston surface on the transport side, which are characterized by a certain radius and a certain height, are located along the penimeter in essentially the same perpendicular plane. If the piston 1 overturns, the requirement for these points is no longer met. By means of an anti-tip element 18 of this type, a contact on the side of the penimeter can thus be maintained with the wall 16 of the cartridge during the entire extraction process, such that together with the

5

10

fifteen

twenty

25

30

35

40

Four. Five

fifty

guiding element 7 described above can prevent a piston deflection.

The ventilation element 60 shown in fig. 8 is lying next to the reinforcing ribs 65. A radially extending reinforcing rib 65 is arranged over a radius, which is smaller than the radius belonging to the ventilation element 60, that is, the reinforcing rib 65 has a smaller distance to the piston axis 9 than the longitudinal axis 70 of the ventilation element. The ventilation element 60 has a bore 75, which joins the transport side 3 of the piston to the drive side 4. The gas enters the bore 75 through two inlet openings

62, 63. The inlet openings are arranged at an angle to the piston surface. The piston surface is in this exemplary embodiment the slit base 76 of a vent 71, which can be configured as in figs. 4, 5 or 6b. The slit base 76 is located in a plane perpendicular to the piston axis 9. The angle 77 between the slit base and the inlet plane of the inlet opening is preferably greater than 0 ° and can be up to 90 °.

The ventilation element has a nozzle 74, which projects on the drive side 4 above the reinforcement ribs. The greater constructive length of the ventilation element facilitates accessibility for a welding tool, whereby its outlet opening 72 is closed after the piston settles. The closure is necessary to prevent an exit of the filling mass, if the cartridge is stored in such a way, that the piston does not adopt the highest position. In addition to this, it may be necessary, in the case of isolated filling masses, that during storage do not come into contact with the air, because chemical reactions can occur between the filling mass and the air.

In addition, it is advantageous that the nozzle 74 is as long as possible, since in this way the channel configured through the bore is lengthened. If filling mass actually reaches one of the input openings 62,

63, the time can be extended until the filling mass reaches the outlet opening. It is expected that, in the case of semi-liquid filling masses that do not configure a defined filling level but a surface composed of elevations and depressions, it should be added that this filling mass enters the ventilation slit and advances to the opening input 62, 63. Before the exit opening is actually reached, the settlement process will be terminated. For this reason, the outlet opening 72 can be welded, without having to fear contamination thereof with the filling mass. Precisely if the filling mass is semi-liquid, its flow rate is so low, even in the case of a pressure compensation that is likely to occur following the settlement process, that the welding work step has already finished before filling dough can exit through the outlet opening. In this way it can be avoided by means of the embodiment shown in fig. 8 a contamination of the outlet opening. Consequently the outlet opening can be welded tightly to the liquids, such that the filled cartridge can be stored in any position for longer periods.

Fig. 9 shows a variant of the piston 1 with a ventilation slit 71 that crosses the entire piston body 72. The parts of the piston 1 with the same function as in fig. 8 carry the same reference symbols. The ventilation element 60 has labyrinth channels 78, 79, which connect the inlet openings 62, 63 to the bore 75. These labyrinth channels form a filtering section, in which filling mass can settle. This prevents the filling mass from reaching the outlet opening 72.

Fig. 10 shows a variant of a piston 1 for filling masses, which tend to chemically modify the plastic material of the piston. The piston 1 comprises a piston body 2, which has a transport side 3, an actuation side 4 opposite the transport side 3, and a piston sleeve 5 as well as a protective element 13. The piston sleeve 5 joins the transport side 3 and the drive side 4 and represents the limitation with the wall 16 of the cartridge 17.

The protective element 13 is configured as a protective disk and covers the piston body 2, such that the piston body is not subjected to the filling mass. The protective element 13 or the piston body 2 has a ventilation channel 14, along which gas can be conducted to an intermediate chamber 12 passing through the protective element. The intermediate chamber 12 extends at least partially between the piston body 2 and the protective element 13. From the intermediate chamber 12 the gas reaches the ventilation element 60, which has been configured here as a single bore 75. This bore flows into a nozzle 74 configured with another bore. The nozzle 74 has an outlet opening 72, which in turn can be closed once the piston settlement is finished.

Naturally, the variants of the ventilation elements shown in figs. 7 to 10 can also be used for an annular piston 51 according to one of figs. 4 to 6b.

Claims (15)

5 10 fifteen twenty 25 30 35 40 Four. Five 1. - Piston (1, 50, 51) for a cartridge to retain a filling mass in a reserve chamber of the cartridge, comprising a piston body (2, 52), which has a transport side (3, 53 ) as well as an actuation side (4, 54) opposite the transport side (3, 53) and a piston sleeve (5, 55), where the piston sleeve (5, 55) is arranged around an axis of piston (9) and the piston body (2, 52) is surrounded perimetrically by the piston sleeve (5, 55), where the piston sleeve has a sealing element to establish a fluid-tight joint between the sealing element of the piston sleeve (5, 55) and an inner wall of the cartridge reserve chamber, such that the sealing element, in the mounting state, establishes a fluid-tight joint between the side of transport (3, 53) and the drive side (4, 54), and the piston body (2, 52) contains a first and a second ventilation element (60, 61), whereby the transport side (3, 53) and the drive side (4, 54) can be connected to each other through a bore (75), characterized in that the piston body (2, 52) has a ventilation slit (71, 73), which is made and arranged on the transport side (3, 53) such that, when the piston (1, 50, 51) is inserted into the cartridge containing the filling mass, gas can be conducted through the ventilation slit (71, 73) to an inlet opening (62, 63) that leads into the hole (75). 2. - Piston according to claim 1, wherein at least one of the first and second ventilation elements (60, 61) is provided a first inlet opening (62) and a second inlet opening (63), which they flow into the hole (75), so that gas can be conducted from the transport side (3, 53) to the drive side (4, 54). 3. - Piston according to claim 1 or 2, wherein a first and a second hole are provided. 4. - Piston according to one of the preceding claims 2 or 3, wherein the ventilation slit (71, 73) is connected to the first and second inlet opening (62, 63). 5. - Piston according to one of the preceding claims, wherein at least one of the holes has a longitudinal axis (70), which is oriented essentially parallel to the longitudinal axis of the piston (9). 6. - Piston according to one of the preceding claims, wherein at least one of the inlet openings (62, 63) is oriented at an angle (77) with respect to the longitudinal axis (70) of the ventilation element (60, 61) . 7. - Piston according to claim 6, wherein the angle (77) is greater than 10 ° to 90 ° inclusive, preferably greater than 20 ° to 90 ° inclusive, especially preferably greater than or equal to 30 ° to 90 ° inclusive. 8. - Piston according to one of the preceding claims, wherein the hole (75) contains at least one inflection. 9. - Piston according to one of the preceding claims, wherein the hole (75) contains at least one curvature. 10. - Piston according to one of the preceding claims, wherein the hole (75) contains at least one throttle element. 11. - Piston according to one of the preceding claims, wherein the minimum bore diameter (75) is greater than 1/40 of the piston diameter. 12. - Piston (51) according to one of the preceding claims, comprising an inner piston sleeve (55), wherein the inner piston sleeve (55) limits the piston body (52) on an inner side (59) turned towards the piston shaft (9), comprising an inner sealing element for establishing a sealing contact with a wall of an inner tube disposed within the inner piston sleeve. 13. - Piston according to one of the preceding claims, wherein on the drive side (4, 54), reinforcing ribs (15, 65) are arranged to join the piston shell (5, 55) to the piston body ( 2, 52) and / or an anti-tip element (18, 64) is arranged. 14. - Extraction device, comprising a piston (1, 51, 52) according to one of the preceding claims. 15. - Extraction device according to claim 14, comprising a cartridge (17) for extracting several components, wherein the components are arranged in reserve chambers of the cartridge, arranged next to each other or coaxially.